Abstract: In order to get reliable construction parameters and design parameters of Suzhou-Nantong Yangtze River Bridge,4 tests of piles were taken,including 7 piles with grouting.According to the results of self-balanced static load tests,not only base resistances were improved after grouting,but also frictional resistances were improved by bettering the characteristics of soils and interfaces between piles and soils.After grouting,the frictional resistances were increased by 12.39%～52.87%,and the base resistances were increased by 1.46～6.21 times.The ratios of frictional resistance increment in the ultimate bearing capacity increment were 56%～88%.